Felt and Tarrant Comptometer

Felt and Tarrant ComptometerDorr E. Felt (1862-1930), an American inventor, devised a calculating machine in 1884 using a wooden macaroni box, meat skewers and rubber bands to make a prototype. The Comptometer, one of the first key-driven calculators with a full numeric keyboard, was patented in 1887 and quickly became a commercial success.